Tabernaesine J (1), an unprecedented vincamine-type indole alkaloid with 6/5/6/6/6/5/5 heptacyclic-ring system, as well as one new biogenetically related vincamine-type indole alkaloid (2), were isolated from leaves of Tabernaemontana pachysiphon. Their structures were established by a combination of HRESIMS, NMR, single crystal X-ray diffraction, and ECD calculation. The unprecedented penta-lactone ring in tabernaesine J (1) was postulated to be derived from acetyl-CoA enolate anion. Alkaloid 2 combined with fluconazole has the potential to overcome fluconazole resistance in Candida albicans. © 2021 SIOC, CAS, Shanghai, & WILEY-VCH GmbH